The invention relates to an apparatus for the transfer of substrates from an initial station configured as a carousel transfer system, through a plurality of process stations, and back to this initial station. The process stations perform the operations, e.g., coating, lacquering, drying, cooling, testing and sorting of the substrates, and manipulators with rotating gripper arms and carousel transfer systems permit the transfer of the substrates from station to station.
U.S. Pat. No. 5,232,505 discloses an apparatus for the automatic molding, coating, lacquering, testing and sorting of workpieces--especially flat, disk-shaped plastic substrates, such as optical or magneto-optical computer data diskettes--having at least one transfer system carrying the substrates from a station at which they are produced, such as an injection molding machine, to the process stations, and having a receiving station for the separate depositing of workpieces finished and tested perfect, and workpieces found defective. The substrate transfer system has carriages moving back and forth along a straight line and with three transfer arms with substrate holders disposed on both sides of the carriage. A vacuum coating apparatus is provided on the one side of the carriage and a stacking system is disposed on the other side of the carriage, with at least one receiver each for substrates found good and for rejected substrates. A carousel transfer system is disposed opposite the injection molding machine in the direction of movement of the carriage, including a turntable with lacquering, drying, printing, image inspection and centering systems. The turntable moves the substrates in a plurality of transport steps--preferably in nineteen transport steps--on a circular path by a full 360 degrees about the vertical axis of rotation of the turntable. The carriage, as it moves in the one direction transfers with its first arm a first substrate in a single step from the pickup station of the dispensing station to the airlock leading into and out of the vacuum coating apparatus and likewise simultaneously with the transport arm shifts a second substrate from the coating station to a lacquering station and likewise a third substrate from the lacquering station to the turntable which rotates step-wise and at the same pace. The carriage in its final movement carries a finished workpiece to the testing apparatus and an already tested workpiece from there to the second receiver.
This known apparatus has the disadvantage that its speed of operation and its operating cycles are determined by the slowest-working process station--the lacquering station--so that the output of the entire apparatus remains limited.